Manufacturing method of liquid crystal panel and deuterium, hydrogen deuteride, or tritium treatment of alignment film

ABSTRACT

In order to improve the state of image irregularities of a liquid crystal panel, a plasma treatment is performed for an alignment film using a treatment gas such as hydrogen and/or deuterium, or a surface treatment is performed in which an alignment film is immersed in deuterium oxide. As a result, moisture contained in the alignment film is removed, and re-adsorption of moisture is also suppressed, thereby reducing image irregularities.

This is a divisional of U.S. patent application Ser. No. 11/680,074,filed Feb. 28, 2007 now U.S. Pat. No. 7,777,848.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a manufacturing method of a liquidcrystal panel and a surface treatment method of an alignment film, andmore particularly, relates to a surface treatment method for suppressingalignment defects which cause image irregularities of liquid crystaldisplay devices.

2. Description of the Related Art

An electronic device called liquid crystal on silicon (LCOS) which isrepresented by an active matrix liquid crystal display panel isgenerally manufactured by sequentially performing many treatmentprocesses on a substrate, such as oxide, silicon, sapphire, or glass.The treatment processes, for example, may include cleaning, thin-filmformation, etching, ion implantation, thermal processing, porous filmformation, alignment film formation, application of liquid crystalsealing agent, and liquid crystal injection.

In general, all the treatment processes are performed in respectivemanufacturing apparatuses which are disposed in a clean room. In thetreatment processes, when semiconductor substrates are transported fromone process to another process, the substrates are exposed to theatmosphere in the clean room. A manufacturing method of an active matrixliquid crystal display panel has been disclosed.

In addition, in order to remove moisture in a semiconductor devicemanufacturing process, a method has been disclosed in Japanese PatentLaid-Open Nos. 2004-310037 and 2005-62877 in which a substrate isirradiated with a noble gas or a hydrogen active species.

However, in a liquid crystal panel manufactured in accordance with amethod of the related art, image irregularities were generated in somecases. In particular, as a liquid crystal projector application, whenthe liquid crystal panel was continuously irradiated with intensivelight, apparent image irregularities sometimes occurred after the panelwas used for a long period of time.

According to intensive research and consideration carried out by theinventors of the present invention, it is believed that moisture whichadheres to an alignment film aligning liquid crystal molecules is one ofthe reasons causing image irregularities of a liquid crystal panel.

For example, when a solid substance is exposed to the atmosphere of aclean room, it adsorbs moisture in the clean room on the surface thereofquickly. In a liquid crystal panel, oxide, such as a silicon oxide,which is formed by oblique deposition, is sometimes used as an inorganicalignment film. In this case, the inorganic alignment film quicklyadsorbs moisture in the atmosphere when it is recovered from adeposition vacuum chamber. In particular, since the oblique depositionfilm is a film which is grown in an oblique direction with respect to asubstrate, the influence of moisture adsorption as described above isconsiderable. As a result, the adsorbed moisture desorbs as steam in asubsequent step and then diffuses into the liquid crystal, resulting inimage irregularities and degradation in light durability and the like.

As described above, it was found that moisture molecules, which adsorbon the inorganic alignment film, variously affect the properties of aliquid crystal device and are partly responsible for causing imageirregularities. In addition, it was also found that, after the processfor forming this alignment film is finished, the adsorption of moisturemust be suppressed.

SUMMARY OF THE INVENTION

The present invention provides a manufacturing method of a liquidcrystal panel, which can efficiently remove moisture contained in analignment film formed by oblique deposition using an inorganic materialor the like and which can also prevent re-adsorption of moisture, and asurface treatment method of an alignment film.

A first aspect of the present invention provides a method formanufacturing a liquid crystal panel, including the steps of preparingtwo substrates having an alignment film on at least one surface thereof,and disposing a liquid crystal between the two substrates. In the abovemanufacturing method, a surface treatment step is performed in which thealignment film is exposed to an atmosphere containing at least onecomponent selected from the group consisting of deuterium, hydrogendeuteride, and tritium, and after the surface treatment, the liquidcrystal is brought into contact with the alignment film.

A second aspect of the present invention provides a method formanufacturing a liquid crystal panel, including the steps of preparingtwo substrates having an alignment film on at least one surface thereof,and disposing a liquid crystal between the two substrates. In themanufacturing method described above, a surface treatment step isperformed in which the alignment film is exposed to deuterium oxide, andafter the surface treatment, the liquid crystal is brought into contactwith the alignment film.

A third aspect of the present invention provides a method for performinga surface treatment of an alignment film, including the step of exposingthe alignment film to an atmosphere containing at least one componentselected from the group consisting of deuterium, hydrogen deuteride, andtritium.

A fourth aspect of the present invention provides a method forperforming a surface treatment of an alignment film, including the stepof exposing the alignment film to deuterium oxide.

In the above surface treatment step according to the present invention,the step can be performed at a pressure preferably in the range of 50 to400 Pa.

According to still another aspect, the present invention is directed toa liquid crystal panel comprising two substrates having an alignmentfilm on at least one surface thereof and a liquid crystal between thetwo substrates, where the liquid crystal panel is formed by performingthe steps of (a) preparing the two substrates having an alignment filmon at least one surface thereof; (b) performing a surface treatment inwhich an alignment film is exposed to (i) deuterium oxide or (ii) anatmosphere containing at least one component selected from the groupconsisting of deuterium, hydrogen deuterium, and tritium, wherebymoisture adsorbed by the alignment film is removed and furtheradsorption of moisture is inhibited; and (c) bringing the liquid crystalinto contact with the alignment film.

In addition, the alignment film can be an inorganic alignment filmformed by oblique deposition. The reason for this is that this alignmentfilm is likely to adsorb water, and in addition, water can be easilyremoved by the method according to the present invention. Furthermore,transistors can also be formed under the alignment film. The reason forthis is that, at the same time as water is removed, dangling bondspresent on gate insulating film interfaces of transistors and onsemiconductor layer surfaces can be terminated by the surface treatmentaccording to the present invention.

In the above methods according to the present invention, the followingconfigurations are included as preferable embodiments. The inorganicalignment film can be formed by oblique deposition. The inorganicalignment film is a silicon oxide film as an inorganic metal compound.The inorganic alignment film is provided on a transparent conductivefilm formed on a glass substrate. The inorganic alignment film isprovided at least on a reflection layer, which is a metal atomic layer,formed on a silicon substrate.

According to one embodiment of the present invention, moisture containedin an alignment film is efficiently removed, and when at least one ofdeuterium, hydrogen deuteride, and tritium is contained in the alignmentfilm, re-adsorption of moisture can be prevented. Hence, an alignmentfilm which has a small water content and which is not likely tore-adsorb moisture can be provided, and in an electronic device usingthe above alignment film, that is, in a liquid crystal panel, the stateof image irregularities and the durability can be improved.

Further features of the present invention will become apparent from thefollowing description of exemplary embodiments with reference to theattached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional view of an example of a treatmentapparatus performing a first treatment method according to the presentinvention.

FIG. 2 is a schematic cross-sectional view of an example of a treatmentapparatus performing a second treatment method according to the presentinvention.

FIG. 3 is a graph showing dehydration effects of various treatmentmethods.

FIG. 4 is a schematic cross-sectional view of an example of a liquidcrystal panel using an inorganic alignment film according to the presentinvention.

FIG. 5 is a schematic cross-sectional view of an oblique depositionapparatus.

FIG. 6 is a flowchart illustrating a manufacturing process of a liquidcrystal panel.

DESCRIPTION OF THE EMBODIMENTS First Embodiment

Hereinafter, with reference to the figures, preferable embodimentsaccording to the present invention will be described. In order tofacilitate the understanding of the present invention, the case in whichhydrogen and/or deuterium is used will be described.

FIG. 1 is a schematic cross-sectional view of an example of a treatmentapparatus performing a first treatment method according to the presentinvention. A treatment apparatus 12 is formed of two air-tight chambers,that is, one chamber is a treatment chamber 6 receiving a substrate 13,and the other chamber is a load lock chamber 11 provided at the frontside of the treatment chamber 6.

A gate valve 10 is provided between the treatment chamber 6 and the loadlock chamber 11.

The substrate 13 provided with an inorganic alignment film on thesurface thereof is transported to the load lock chamber 11 underatmospheric pressure by a transportation device (not shown). In thistransportation, the substrate 13 is transported to the load lock chamber11 from a carrier cassette or the like through an access device 14 suchas a gate valve (not shown). In addition, during the transportation, thegate valve 10 is closed, and hence the inside of the treatment chamber 6is placed in an approximately vacuum state.

Subsequently, the load lock chamber 11 receiving the substrate 13 istightly closed and is then evacuated to a predetermined pressure by anevacuation device 15. Then, the substrate 13 is transported to thetreatment chamber 6 by a transportation device (not shown) in vacuum viathe gate valve 10.

The treatment chamber 6 has a gas supply device 8, a gas inlet 3, anexhaust line 4, an exhaust device 9, a heater stage 5, a microwavegenerator 7, a microwave guide 1, and a microwave transmission window 2.

Using the gas supply device 8 and the gas inlet 3, a treatment gas iscontrolled to flow at a desired flow rate and is then supplied in thetreatment chamber 6. As the treatment gas, deuterium (D₂), hydrogendeuteride (HD), and tritium may be used alone or in combination of atleast two of the above four. In particular, deuterium or hydrogendeuteride is preferably used. In addition, the above treatment gas maybe used after being diluted to a concentration of 10 volume percent withan inert gas such as neon or xenon, and/or hydrogen (H₂).

The exhaust line 4 discharges the treatment gas outside, which wassupplied in the treatment chamber 6.

The exhaust device 9 controls the pressure inside the treatment chamber6 to a desired value based on a measurement result by a pressure sensor(not shown). The exhaust device 9 includes, for example, a conductancevalve, a vacuum pump, and a shut valve.

The heater stage 5 is provided to receive and heat the substrate 13 whenit is treated and can maintain the substrate 13 at a desiredtemperature. In the present invention, the temperature of the heaterstage 5 is controlled in the range of room temperature to 400° C. andpreferably in the range of room temperature to 300° C.

The microwave generator 7 generates microwaves to excite a treatment gasfor plasmarization. Although in this embodiment the treatment gas isplasmarized, when the treatment is performed in an atmosphere of atreatment gas which is excited by a different method, the same effect asdescribed above can also be obtained.

The microwave guide 1 and the microwave transmission window 2 guidemicrowaves into the treatment chamber 6. The microwave transmissionwindow 2 is formed of a dielectric material, such as quartz glass,alumina, or aluminum nitride.

The substrate 13 transported into the treatment chamber 6 is heated to apredetermined temperature on the heater stage 5. In addition, thesubstrate 13 is treated under a predetermined pressure with plasma of atreatment gas, which contains deuterium or hydrogen and deuterium,excited by microwaves. The above pressure is preferably in the range of50 to 400 Pa. When the pressure is less than 50 Pa, hydrogen and/ordeuterium ions, which have high energy in the plasma, are likely toreach the substrate 13. On the other hand, when the pressure is morethan 400 Pa, active species of deuterium are not likely to reach thesubstrate 13, and hence the efficiency of moisture removal isconsiderably degraded.

In the plasma treatment according to the present invention, surface waveplasma generated by microwaves is preferably used. As a result, sincehigh density plasma is obtained, and high density deuterium activespecies are supplied, an efficient moisture removal treatment can beperformed.

In the present invention, plasma treatment apparatuses, each of whichhave an airtight chamber receiving the substrate 13 and which are usedfor semiconductor manufacturing processes, may be used. For example, aplasma CVD apparatus used in a thin-film forming step may be applied.Alternatively, a plasma etching apparatus used in an etching step mayalso be applied.

In this embodiment, although a single-wafer type treatment apparatushaving the load lock chamber 11 is used, the apparatus is not limitedthereto. For example, the structure may be formed in which the load lockchamber 11 is not provided, and in which the treatment chamber 6 isdirectly placed in the atmosphere and in an approximately vacuumcondition in an alternate manner. Alternatively, the structure in whicha plurality of the substrates 13 is simultaneously treated in thetreatment chamber 6 may be formed.

According to the present invention, an oxide film formed by obliquedeposition can be efficiently dehydrated even when the treatmenttemperature is room temperature.

FIG. 2 is a schematic cross-sectional view of an apparatus performing asecond treatment method according to the present invention. Thisapparatus has a deuterium oxide (D₂O) bath 31, and in this bath 31, aheater stage 32, which can optionally control the temperature of thebath, is provided. The heater stage 32 has a mechanism in which thetemperature is controlled to a desired temperature by an electric sourceand a temperature control circuit (not shown). In addition, the heaterstage 32 may be provided with a function (not shown), such as ultrasonicvibration, so that the efficiency of immersion in deuterium oxide (D₂O)can be improved by applying energy to a substrate 33.

The substrate 33 provided with an inorganic alignment film on thesurface thereof, which is to be dehydrated, is immersed in a deuteriumoxide (D₂O) bath solution 34 filled in the bath 31. The time for theimmersion and the temperature of the D₂O solution 34 may be selected asdesired. The solution temperature for the immersion under theatmospheric pressure is preferably 0 to 100° C. and more preferably 20to 95° C. The time for the immersion is preferably in the range of 0.1seconds to 48 hours and more preferably in the range of 2 seconds to 24hours. The concentration for the immersion with respect to pure water ispreferably 1 to 100 volume percent and more preferably 20 to 100 volumepercent. After the immersion in the deuterium oxide, liquid droplets areremoved by blowing a N₂ gas onto the surface of the inorganic alignmentfilm.

Even when the inorganic alignment film is immersed in the deuteriumoxide solution as described above, a dehydration treatment can beperformed as is the case of the inorganic alignment film processed bythe above plasma treatment.

FIG. 3 shows the results of the first treatment (plasma treatment) andthe second treatment (immersion in D₂O), according to the presentinvention, besides the result of non-treatment.

In general, in a thermal differential spectroscopic (TDS) analysis, asample is heated at a predetermined rate in vacuum, and desorption gasesare then measured by a mass analyzer. Accordingly, as for a gas specieshaving a specific molecular weight, the temperature dependence of adesorption amount (relative value) can be measured. FIG. 3 shows theresults obtained when a water molecule (molecular weight of 18) wasmeasured.

In general, when the desorption data of a water molecule (molecularweight of 18) of a silicon oxide formed by oblique deposition ismeasured, the information of surface adsorption water from roomtemperature to approximately 300° C. can be obtained.

As shown in FIG. 3, water desorption from silicon oxide films processedby a deuterium plasma treatment, and an immersion treatment in deuteriumoxide is not observed at all from room temperature to approximately 300°C. as compared to that from a non-treated silicon oxide film. From theseresults, it is apparent that the deuterium plasma treatment, and theimmersion treatment in deuterium oxide (this is also one type of surfacetreatment) can efficiently remove adsorption water on the oxide filmsurface.

In particular, although a substrate provided with a silicon oxide filmtreated by deuterium was held in a clean room over two months after thetreatment, the TDS spectrum had the same tendency as that obtainedbefore. Accordingly, it was found that the above moisture-adsorptionpreventing effect lasts for a significantly long time. Hence, as thesurface treatment of alignment films in mass production, the treatmentby deuterium is preferable.

By the first or the second treatment of the present invention, besidesprimary constituent elements forming the alignment film, the alignmentfilm according to the present invention contains at least deuterium. Thecontent of the deuterium can be considerably changed in the range of1×10¹² to 1×10²² (cm⁻³) in accordance with the shape of the inorganicalignment film. The deuterium may be terminated by dangling bonds ofprimary constituent elements, which are generated on surfaces, in thevicinity thereof, in defects, and in spaces to which moisture of theinorganic alignment film is adsorbed, to form hydrogen bonds and/ordeuterium bonds.

In addition, for the inorganic alignment film of the present invention,silicon nitride, silicon oxide, or silicon oxynitride may be used, andin particular, a compound containing silicon and at least an oxygen atom(O) is preferable.

The inorganic alignment film according to the present invention is afilm having a columnar structure, and the columnar growth direction maybe perpendicular or inclined to the substrate. In addition, theinorganic alignment film may be a film in which planar layers areoverlapped with each other and are aligned, and the planar layers may bedisposed perpendicular or inclined to the substrate.

The surface structure of the inorganic alignment film according to thepresent invention may have an irregular shape in conformity with thecross-sectional structure described above. In addition, in order toreduce the irregularities, planarization may be performed by polishing.

The inorganic alignment film according to the present invention may be aporous film having a plurality of pores therein. The porous filmaccording to the present invention is classified by the size of pores,and a film having pores of less than 2 nm, a film having pores in therange of 2 nm to 50 nm, and a film having pores of more than 50 nm arecalled a microporous film, a mesoporous film, and a macroporous film,respectively.

As defined by IUPAC, the pores forming the mesoporous film indicatespores having a diameter in a meso region of 2 nm to 50 nm, as describedabove. In addition, in the pore diameter distribution evaluated by theBerret-Joyner-Halenda (BJH) method from an adsorption isotherm which isobtained by a gas adsorption method, 60% or more of pores is includedwithin a range of 10 nm. The range of 10 nm indicates the range in whichthe difference between the maximum and the minimum is 10 nm, forexample, in which the maximum and the minimum are 15 nm and 5 nm,respectively.

A device using the inorganic alignment film according to the presentinvention will be particularly described.

FIG. 4 is a schematic cross-sectional view of a liquid crystal panelusing the inorganic alignment film of the present invention formed byoblique deposition. A sealing member (sealing material) provided alongthe periphery of the substrate is not shown.

As shown in this figure, an inorganic alignment film 43 has a columnarstructure, and a growth angle of the columnar structure can be evaluatedby a SEM cross-section observation. When the inorganic alignment film 43thus formed is processed by the treatment according to the presentinvention, the presence of deuterium atoms can be confirmed by a SIMSanalysis.

As a glass substrate 41 in FIG. 4, a material may be optionallyselected, for example, from a quartz glass, a non-alkali glass, and aninexpensive soda-lime glass in accordance with the specification, thatis, in accordance with desired optical properties, of a liquid crystaldevice.

In view of surface properties and electrical properties, an ITO film 42may have a thickness in the range of 10 to 200 nm and preferably 15 to100 nm.

The inorganic alignment film 43 of the present invention may be formedby performing vacuum deposition (or vacuum evaporation) of silicon oxidewhile the substrate is inclined.

An oblique deposition film of silicon oxide having a columnar structureis obtained by the vacuum deposition. The film structure of an obliquedeposition film can be controlled by an incident angle.

FIG. 5 is a schematic view showing the structure of an obliquedeposition apparatus. The incident angle is defined as an angle betweenthe normal of a substrate 52 and an incoming direction thereto from adeposition source 55. Reference numeral 53 indicates a substrate holderwhich can hold and heat the substrate 52.

When the inorganic alignment film of the present invention is formed ofan oblique deposition film, the incident angle may be set in the rangeof 30° to 85° and preferably 40° to 80° in accordance with variousproperties necessary for liquid crystal orientation. In particular,since having a strong relationship with a pretilt angle of the liquidcrystal orientation, the incident angle is a very important parameter todesign element properties of a liquid crystal panel.

On a silicon substrate 44, for example, a liquid crystal panel drivesemiconductor circuit is formed. That is, the silicon substrate 44 is asemiconductor substrate having single crystal silicon transistorsdisposed in a matrix at the surface side. Alternatively, instead of thesilicon substrate 44, a glass substrate having non-single crystaltransistors disposed in a matrix may also be used. A reflection film 45is also used as an electrode, and in this embodiment, a metal layer madeof aluminum or an aluminum alloy may be used. In the case of a verticalorientation mode, a liquid crystal material having negative dielectricanisotropy is used as a liquid crystal LC. The liquid crystal of thepresent invention is not limited to a liquid crystal having a verticalorientation mode, and a liquid crystal having an orientation mode calledan in-plane switching (IPS) mode or a twisted nematic (TN) mode may alsobe used.

In a manufacturing process of a liquid crystal panel, after an obliquedeposition film of silicon oxide or the like is formed as the inorganicalignment film, when the above surface treatment is performed,degradation in light durability of a liquid crystal device, which iscaused by contamination of the inorganic alignment film with moisture,can be significantly suppressed. FIG. 6 is a flowchart of a process formanufacturing a common liquid crystal panel. Hereinafter, individualsteps will be described with reference to a process for manufacturingthe liquid crystal panel shown in FIG. 4 by way of example.

First, after the substrates 41 and 44 are washed (step 61), the ITO film42 used as a transparent electroconductive film is formed on thesubstrate 41, and the reflection film 45 is formed on the othersubstrate 44 (step 62). Next, in a vacuum container 51 shown in FIG. 5,approximately 100 layers of SiO₂ are formed by an oblique depositionmethod as the inorganic alignment film 43. A nitrogen supply mechanism(not shown) provided for the vacuum container 51 supplies nitrogentherein, so that the pressure in the vacuum container 51 is returned tothe atmospheric pressure. Subsequently, the substrates 41 and 44 eachprovided with the oblique deposition film are recovered.

In general, in view of performance stability of the device, the stepsdescribed above are preferably performed under clean conditions, such asin a clean room, in which the control of temperature and humidity isperformed. Subsequently, as shown in FIG. 1, the substrates 41 and 44are placed in the microwave plasma generator (treatment apparatus) 12and are then processed by deuterium plasma treatment. Alternatively, thesubstrates 41 and 44 are immersed in the bath 31 of deuterium oxideshown in FIG. 2, so that the surface treatment of the inorganicalignment films is performed. As described above, at an appropriatetiming after an alignment film forming step 63 and before a liquidcrystal injection step 67, the surface treatment according to thepresent invention is performed, so the a dehydration treatment (surfacetreatment step of the present invention) of the inorganic alignment film43 is performed.

Next, a sealing agent is applied along the periphery of one of thesubstrates (step 64), and the substrates 41 and 44 are disposed to faceeach other with a predetermined distance therebetween so that thealignment films 43 are placed inside (step 65). Subsequently, a step ofcuring the sealing agent (step 66) is performed, for example, byirradiation of predetermined ultraviolet rays when a UV curing typesealing agent is used or by heat application when a thermosetting typesealing agent is used, so that bonding of the substrates is completed.An opening is formed in the sealing agent, and a liquid crystal isinjected through this opening by a vacuum liquid crystal injector (step67). After the injection of the liquid crystal is completed, an openingsealing agent is applied to the opening (step 68) and is then cured by acuring process, such as UV irradiation, in a step 69, thereby formingthe liquid crystal panel.

In the present invention, a drip injection method may also be used inwhich after the inorganic alignment films are surface-treated, a liquidcrystal is dripped on one of the substrates and is then sandwiched withthe other substrate, followed by sealing along the peripheries of thesubstrates. In addition, in the present invention, from the surfacetreatment of the inorganic alignment films to the step of sandwichingthe liquid crystal between the substrates, the inorganic alignment filmsprocessed by the surface treatment are preferably not to be irradiatedwith ultraviolet rays or rays having a wavelength shorter than that.That is, after the surface treatment of the inorganic alignment films isperformed and before the liquid crystal is brought into contacttherewith, it is preferable that the surfaces of the inorganic alignmentfilms be at least shielded from ultraviolet rays and rays having awavelength shorter than that.

EXAMPLES Example 1

After a liquid crystal panel was formed in accordance with the flowchartshown in FIG. 6, a light durability test of the liquid crystal panel wasperformed. The surface treatment conditions for an inorganic alignmentfilm and the results of the light durability test are shown in Table 1.

As a comparative example, after the formation of oblique depositionfilms, a liquid crystal panel using oblique deposition films, which werenot processed by plasma treatment, was formed.

The light durability test for the liquid crystal panel was performedunder a condition in which the light intensity was higher than that inwhich a common product was used, and image irregularities of the liquidcrystal panel could be confirmed by microscope observation.

In the light durability test of this example, the panel temperature washeld at 70° C., and continuous irradiation of white light at 10 W/cm²was performed. The time at which image irregularities were not generatedby the continuous irradiation was measured, and a time of 1,000 hours ormore, 800 hours or more, and less than 800 hours were represented by

, ◯, and x, respectively.

As a result, it was found that the liquid crystal panel formed by thetreatment method of this example has excellent light durability, andthat a liquid crystal device has high performance stability.

When a plasma treatment is performed using HD instead of D₂, the sameresult as described above can also be obtained. Accordingly, as apparentfrom the results of the light durability test, the durability of theliquid crystal panel according to the present invention, which is formedby using the treatment method of the present invention, can besignificantly improved.

TABLE 1 Gas Flow Rate Pressure MW Treatment Light (sscm) (Pa) power (W)Time (min) Durability Comparative No No No No ◯ Example H₂ + D₂ 200 100500 2 ⊚ D₂ 200 100 500 2 ⊚ HD 200 100 500 2 ⊚

Example 2

A liquid crystal panel was formed in a manner similar to that in Example1 except that, as a dehydration treatment of the inorganic alignmentfilm, immersion in deuterium oxide was performed instead of the plasmatreatment. The treatment conditions and the results of the lightdurability test are shown in Table 2.

TABLE 2 Immersion Immersion Light Condition Time (min) DurabilityComparative Example No No ◯ Immersion in D₂O 60° C. 5 ⊚

While the present invention has been described with reference toexemplary embodiments, it is to be understood that the invention is notlimited to the disclosed exemplary embodiments. The scope of thefollowing claims is to be accorded the broadest interpretation so as toencompass all modifications, equivalent structures and functions.

This application claims the benefit of Japanese Application No.2006-055973 filed Mar. 2, 2006, which is hereby incorporated byreference herein in its entirety.

1. A method for manufacturing a liquid crystal panel, comprising thesteps of: preparing two substrates having an alignment film formed on atleast one surface thereof; and disposing a liquid crystal between thetwo substrates; wherein after said preparing step and before saiddisposing step a surface treatment step is performed in which thealignment film is exposed to an atmosphere containing at least onecomponent selected from the group consisting of deuterium, hydrogendeuteride, and tritium, and after the surface treatment, the liquidcrystal is brought into contact with an exposed surface of the alignmentfilm, and wherein a concentration of the at least one component in theatmosphere is 10 vol % or more.
 2. The method for manufacturing a liquidcrystal panel, according to claim 1, wherein the surface treatment stepis performed at a pressure in the range of 50 to 400 Pa.
 3. The methodfor manufacturing a liquid crystal panel, according to claim 1, whereinthe alignment film is an inorganic alignment film formed by obliquedeposition.
 4. The method for manufacturing a liquid crystal panel,according to claim 1, further comprising a step of forming transistorson at lease one of the substrates.